Recently I bought a new nVidia videocard called something like GT640, it started out fine initially, but I started getting this strange problem each time after watching movies on my PC, when I exit the videoplayer, Windows would freeze for a few seconds and the display mode changes to 640x480x16 (16 colours) and said "The display driver has crashed....", and the only option is to reboot the system.

Is this a software problem? I never had any problems with my previous videocards (ATI or nVidia), how do you fix this problem? it's frustrating.

The obvious things should go ahead and be gotten out of the way first which is make sure you have the latest drivers and the latest version of whatever video player software you use.

If that doesn't work or you already have the latest then try a different video player. For regular video VLC player is good.

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"This seems like a good time for a drink, and a cold calculated speech with sinister overtones. A speech about politics, about order, brotherhood, power. But speeches are for campaigning. Now is the time for action."

It was not like that, it happens when I connect my computer to TV using the HDMI port on the videocard, when I start to play video, Windows just crashes with an error message that said the video driver has stopped working, and I am already using the latest driver and video player.

I tried to use GOM player, Media Player Classic, and Windows Media Player, they all give the same errors.